This invention relates generally to the field of liquid gel chromatography, and, more particularly to a magnetic resonance chromatography system that separates molecules such as cells and proteins into different populations based upon their interactions with a magnetic field oscillating at radio frequencies.
Liquid gel chromatography (LGC) is an established laboratory technique for the differential fractionation and separation of molecules. The underlying premise for simple LGC is that molecules elute from a gel bed in order of decreasing molecular weight. Generally, gel particles fill a chromatography column to form a bed. When the molecules to be partitioned, such as cells or proteins are introduced and driven through the bed by supplemental eluent, the molecules separate on the basis of molecular weight. That is, the larger molecules separate and elute first. Thus, the elution order is one of decending size. Since liquid gel chromatography in general and gel permeation type LGC in particular, are well known by those practicing in the related arts, and are adequately described in references such as U.S. Pat. No. 3,002,823 to P. G. M. Flodin et al further elaboration is superfluous.
Though a multitude of refinements have been developed to improve the distinctness of the partitioning and increase its rate, better resolution of molecular species on the basis of weight and shape continues to be sought. This is particularly true when complex cell or protein populations, such as biological fluids are being separated. In such cases, the conventional approaches involve successive LGC filtration steps or the concurrent use of other perturbation techniques to alter the environment during the LGC process. For example, detergents and salts have been used to provide unique environmental effects.
Electric resonance chromatography (ERC) as described in the inventor's U.S. Pat. No. 4,238,327 issued Dec. 9, 1980 is a recent example of a new refinement in LGC molecular separation utilizing an applied electric field for a unique effect. In this refinement conventional LGC is improved so that ERC can both accelerate separation and accentuate the ability to distinctly identify molecular groups within the population that possess an electric dipole moment (that is, charge separation) and, thus, interact with the applied electric field. In gel filtration terms, the elution time is decreased for these species while the zones are narrowed.
Although the above known techniques have been used successfully in most instances, in the ever expanding field of chromatography there always exists a need for alternative systems to separate molecules. For example, there exist proteins and cells that do not possess a net electric dipole (charge separation) moment even though they possess charged groups. These species will not interact with an applied electric field as described in U.S. Pat. No. 4,238,327 referred to above. Therefore, by the development of further and other techniques more efficient and reliable separation would be attainable.